As long as the underlying token (Steem) is volatile and the markets illiquid, there is still a risk in doing this conversion even if it is the right decision. I did the same a few days ago. The problem is that it's the mean price of Steem over the week period which will determine the outcome, and the final price also matters a lot.

It's a gamble, but one which is in your favour for every cent below $1 SBD are trading at. Also, SBD dropping in price after you bought is not relevant, in fact it only helps for you to make more profit by doing the exact same thing again after the week with even more SBD available to you.